902 



SCIENCE 



[N. S. Vol. XL. No. 1042 



■ways. Some of these possible chemical reac- 

 tions are as follows : 



■ + N+e + e-(-6 = N0 (1) 



-fN = NO 



+ lJ2 = N0 + N 

 + |j + e + e = NO 

 + S" + e = NO 

 -|-N2 + e = N0 + N 

 +"W3 + e = NO + N2 



(2) 

 (3) 

 (4) 

 (5) 

 (6) 

 (7) 



N. + 02 = 2NO. 

 In the place of O we might place Oj, O,, O, 

 O, Oj, Oj and 0. We thus have 56 possible 

 chemical reactions to represent the filiation 

 of nitrogen. No doubt only a few of these re- 

 actions actually take place though all are pos- 

 sible, provided all these kinds of ions exist 

 where the oxides of nitrogen are being formed. 



The comparative probability of some of 

 these reactions is very small, especially when 

 more than two products take part in the reac- 

 tion. Since the oxides of nitrogen are appar- 

 ently not removed from the gases by the elec- 

 tric field, it is probable that the oxide of ni- 

 trogen centers are not charged. Hence it fol- 

 lows that reactions which involve the presence 

 of an electron are improbable. The apparent 

 fact that the reaction is " electrical " would 

 indicate that the reactions N^ + Oj and 

 N -|- O are not probable. The latter is in ac- 

 cord with the view that active nitrogen con- 

 sists of N and that N does not take any active 

 part in the formation of oxides of nitrogen. 



It seems quite probable therefore that the 

 main reaction that results in the formation of 

 oxides of nitrogen is 



1?2 + Oj -1- 43000 calories — 2N0 

 This type of ionization is produced by cath- 

 ode rays or rapidly moving electrons accord- 

 ing to Thomson and others and accordingly 

 this equation would indicate that the oxidiza- 

 tion of nitrogen is indirectly due to cathode 

 rays. It may be for this reason that thermi- 

 onic electron radiations may play an impor- 

 tant role in the formation of oxides of nitrogen 

 in the various arc processes. In contrast to the 

 above reaction is the reaction resulting in the 



formation of ozone. Ozone must necessarily 

 be formed under conditions where some O., is 

 dissociated. 



The above reaction may be only one of sev- 

 eral reactions, and under different conditions 

 of pressure and temperature these reactions 

 may be of relatively quite different degrees 

 of importance. 



Efficiency of the Nitrogen-fixing Process 

 We can get some idea of the inefficiency of 

 the present methods of oxidizing nitrogen when 

 we consider that when gram molecular weights 

 of the gases are used one has : 



N"^ -I-' O, + 43,000 calories = 2N0 

 approximately. The amount of energy used in 

 this reaction is therefore about 1.7(10)^^ ergs 

 for about 126 gm. of nitric acid. Assuming 

 80 gm. of nitric acid to be made per kilowatt 

 hour, we should have an energy consumption 

 of about 5(10)^^ ergs or an efficiency of about 

 4 per cent. 



Nitrogen Fixation and Our Economic Life 

 The small percentage efficiency of the pres- 

 ent methods for oxidization compared with 

 the theoretical efficiency indicate that im- 

 provements in the present methods would yield 

 most important results. At the present time 

 sodium nitrate sells for about $45 per ton. 

 If the efficiency of the oxidation method could 

 be increased so that calcium nitrate could be 

 sold for $6 or $8 per ton, it would change our 

 economic life fundamentally. Food products 

 would be greatly decreased in value, real in- 

 tensive farming could be pursued, suburban 

 homes could easily be made self supporting and 

 " abandoned " farms could be reclaimed. 

 Probably no other one scientific development 

 would so materially add to the material well 

 being of the people as this. 



One of the reasons for the high cost of liv- 

 ing is the fact that our soil fertility is diffi- 

 cult to maintain. Continued cropping will 

 eventually impoverish the most fertile soils if 

 the crops are not replaced. Cheap nitrogen 

 fertilizers will not only practically restore 

 virgin fertility, but will permit of the continual 



